What is the recommended workup for a patient with constant pulsatile tinnitus (ringing in the ears synchronized with the heartbeat)?

Workup for Constant Pulsatile Tinnitus

Order CT angiography (CTA) of the head and neck with contrast as the first-line imaging study for constant pulsatile tinnitus, as this symptom indicates an underlying vascular or structural abnormality in over 70% of cases, including life-threatening causes like dural arteriovenous fistula or arterial dissection that can result in catastrophic hemorrhage or stroke if missed. 1, 2

Immediate Clinical Assessment

Before ordering imaging, perform these specific evaluations:

• Otoscopic examination to identify vascular retrotympanic masses (paragangliomas appear as red pulsatile masses behind the tympanic membrane) 1, 2
• Auscultation over the periauricular area, mastoid, orbit, and neck to detect objective tinnitus (audible bruit strongly indicates vascular pathology) 1, 2
• Jugular/carotid compression test - if tinnitus is relieved by gentle compression, this suggests venous etiology (sigmoid sinus abnormalities, jugular bulb variants) or arterial dissection 1, 2
• Neurologic examination to identify focal deficits that would suggest intracranial pathology requiring emergent evaluation 1
• Determine laterality - unilateral pulsatile tinnitus has higher likelihood of identifiable structural cause compared to bilateral 1, 2

First-Line Imaging Strategy

The imaging approach depends on suspected etiology, but CTA is the most versatile first-line study:

Order CTA Head and Neck with Contrast When Suspecting:

• Dural arteriovenous fistulas (8% of cases - can cause hemorrhagic/ischemic stroke) 1, 2
• Arterial dissection (life-threatening, requires urgent identification) 1, 2
• Atherosclerotic carotid artery disease (most common cause at 17.5% of cases) 1, 2
• Arteriovenous malformations 1, 2
• Sigmoid sinus diverticulum or dehiscence 1, 2

Use mixed arterial-venous phase timing (20-25 seconds post-contrast) to capture both arterial and venous pathology in a single acquisition 1

Order High-Resolution CT Temporal Bone (Non-Contrast) When Suspecting:

• Paragangliomas/glomus tumors (16% of cases - visible as retrotympanic mass on otoscopy) 1, 2
• Jugular bulb abnormalities (high-riding jugular bulb, dehiscence of sigmoid plate) 1, 2
• Superior semicircular canal dehiscence 1, 2
• Aberrant venous anatomy 1, 2

Note: CTA source images can be reconstructed to create dedicated temporal bone CT images without additional radiation exposure 1

Mandatory Audiologic Testing

• Order comprehensive audiologic examination within 4 weeks including pure tone audiometry, speech audiometry, and acoustic reflex testing for any constant pulsatile tinnitus 1
• This is essential even if the patient denies hearing loss, as mild asymmetric hearing loss may indicate retrocochlear pathology 1

Second-Line Imaging (If Initial Studies Negative)

• Order MRI brain with contrast and MR angiography (MRA) when CT/CTA are negative but clinical suspicion remains high, or for suspected cerebellopontine angle lesions 1, 2
• Consider catheter angiography for definitive characterization if dural AVF or AVM is suspected but not clearly identified on noninvasive imaging 1

Critical Causes Not to Miss

These conditions require urgent identification:

• Dural arteriovenous fistula - can present with isolated pulsatile tinnitus before catastrophic hemorrhage 1, 2
• Arterial dissection - requires urgent anticoagulation or endovascular intervention 1, 2
• Idiopathic intracranial hypertension - second most common cause (especially in young, overweight women with headaches); can cause permanent vision loss if missed 1, 2
• Paragangliomas - highly vascularized tumors requiring specialized surgical approach 1, 2

Common Pitfalls to Avoid

• Never dismiss pulsatile tinnitus as benign without imaging - identifiable causes exist in >70% of cases 1, 2
• Do not order MRV alone - it is insufficient for evaluating pulsatile tinnitus; CT temporal bone or CTA should be the initial study 1
• Do not use the same protocol as nonpulsatile tinnitus - bilateral, symmetric, nonpulsatile tinnitus does NOT require imaging, but pulsatile tinnitus (even if bilateral) always does 1
• Inadequate otoscopic examination leads to delayed diagnosis of paragangliomas that are visible on direct visualization 1, 2
• Missing intracranial hypertension in the classic demographic (young, overweight women) can result in irreversible vision loss 1

Special Populations

Young overweight women with headaches and pulsatile tinnitus:

• High-risk demographic for idiopathic intracranial hypertension 1
• Requires ophthalmologic evaluation for papilledema 1
• Pulsatile tinnitus from IIH responds dramatically to treatment in nearly 100% of cases 1